Malicious PDF — malware analysis report

Static analysis result for SHA-256 b336f8ff47e51f54…

MALICIOUS

PDF

92.9 KB Created: 2021-09-16 16:49:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 83e434ceeaa3475627e9e439fb293540 SHA-1: 2eaab9c3af1bda379f5fb703a05986e33b93a0ae SHA-256: b336f8ff47e51f546d5bcece0d50bb00664ce199ed2c4233991de2e89f224d66
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple external links, with one specifically flagged as a random URL link to a suspicious PDF. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to potentially harmful content, aligning with phishing or malware delivery tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://successstudio.net/userfiles/file/putedafuko.pdf In PDF document text
    • http://stefanourso.com/public/userfiles/file/14914116563.pdfIn PDF document text
    • https://tidurmalam2.com/contents/files/mafedelinerus.pdfIn PDF document text
    • https://marathonlaval.com/userfiles/files/kugedak.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/mupanekesawewiz.pdfIn PDF document text
    • http://ylphs.com/ckfinder/userfiles/files/waposatukago.pdfIn PDF document text
    • https://aradmissions.com/ci/userfiles/files/falumotusovurosozitef.pdfIn PDF document text
    • http://homeopathyhongkong.cn/files/73623334015.pdfIn PDF document text
    • http://thuaphatlailongthanh.vn/upload/contentFile/minhchau/file/rilunojidivesomitefediwul.pdfIn PDF document text
    • http://veterinarioassociatopacinidallatorre.eu/userfiles/files/luzokoditozezoduxatozad.pdfIn PDF document text
    • http://kurskodkb.ru/page_edit/_samples/userfiles/files/59207946873.pdfIn PDF document text
    • https://www.piramideidiomas.com/ckfinder/userfiles/files/30406114635.pdfIn PDF document text
    • https://southernwashpros.com/nbloom/fckuploads/file/rabefulake.pdfIn PDF document text
    • https://luminex.pl/upload/file/nanovupagatidutitakexub.pdfIn PDF document text
    • http://veterinariogiardinelli.it/userfiles/files/34407852309.pdfIn PDF document text
    • http://sallytour.com/FileData/ckfinder/files/20210916_F4234621BBD555B5.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/bb5cf4d92a249a455ed1c1a4ad2dc1ed/tasigotarivozen.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131b7f642887---vakerefufugelelij.pdfIn PDF document text
    • http://ldkxzzs.com/images/userfiles/file/zuxirivuzuxo.pdfIn PDF document text
    • http://karate-talence.com/newsite/userfiles/files/34903143091.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=beneath+us+full+movie+freePDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010961.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10961 17224 bytes
SHA-256: a4ccf90e7a5939b7e33e81d94cff6bf775ce6952d5961e829b400d6c7a057bbf
font_01_sfnt_off000135f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135F2 10696 bytes
SHA-256: 2fc81b26add4b3d2f169b6c14221421a720a1134cc65badd38fd17c7ecb82ab0
font_02_sfnt_off00014e52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14E52 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1